The Scot was furious that it was he who alerted officials to the incident, telling umpire Nico Helwerth when he returned to the court: “I had to tell them because no-one knows the f***ing rules.”

Discussing the matter after Verdasco’s 7-5 2-6 6-4 6-4 victory, Murray said: “I went and told the supervisor. I said, ‘What are you guys doing? I mean, there’s clear rules here and you’re allowing this to take place. I don’t get it.’

“Then he ran through, ‘Oh, you’re not allowed to speak.’ They obviously weren’t in there for long, but you’ve got to do better than that. This is one of the biggest events in the world.”

Verdasco flatly denied any such rule breach had taken place, claiming that while his coach was in the locker room, he spoke only to another player, Marcos Baghdatis, and the Cypriot’s coach.

Verdasco said: “Obviously if Andy says that, I don’t want to say that he lies, but I didn’t talk one word with my coach or any one member of my team. I know exactly the rule and I don’t want to be the one breaking it.”

With tournament organisers apparently unable to shed any light on what happened, it was a case of one man’s word against the other – and Murray was determined to make sure it was he who had the last one.

In a post on Instagram, Murray wrote: “I’m off to get a health check as apparently I’ve started imagining things,” followed by the hashtag #liarliarpantsonfire.

Nick Kyrgios, who has history with Verdasco, also weighed in on the debate, saying of the coaching accusations on Twitter: “Let’s be real, very believable because it is Verdasco lol.”

Novak Djokovic and Roger Federer advance through to US Open second round

Novak Djokovic engaged “survival mode” as he battled past Marton Fucsovics in brutally hot and humid conditions at the US Open.

Four players retired mid-match as conditions took another step up in intensity on Tuesday and for a while it looked as if Djokovic might become the fifth before he recovered to win 6-3 3-6 6-4 6-0.

He called the doctor during the second set and trailed by a break in the third but took advantage of the tournament’s new extreme heat rule for the men, allowing a 10-minute break between the third and fourth sets, and returned to the court refreshed.

Djokovic, who has found similar conditions difficult in the past, said: “We obviously both struggled. It was survival mode. Credit to Marton, he’s a great fighter.

“I was actually praying that the next moment I get to feel better. I definitely wasn’t feeling great for most of the three sets. But you have these kind of days. I’m not the only one, a lot of the players struggled. I’ll take the win.”

Regarding the heat rule, Djokovic said: “I want to thank the US Open for allowing us to have a 10-minute break. Marton and I were in ice baths next to each other. We were naked in the ice baths and it was a quite wonderful feeling.”

Fucsovics believed the conditions were unplayable, saying: “It was fun to play in the Arthur Ashe Stadium, the first time for me, first time against Djokovic, but it wasn’t fun to play in the heat. I was dying after each point. It was too hot for tennis. It’s dangerous.”

Djokovic arrived in New York as many people’s favourite for the trophy after beating Roger Federer to become the first man to win all the nine different Masters titles in Cincinnati last weekend.

It was smooth sailing initially against Fucsovics as Djokovic won the first set but he soon began to look fatigued and very uncomfortable in the energy-sapping conditions.

Perhaps aware he needed to finish the match quickly, the sixth seed destroyed a racket after failing to break the Fucsovics serve for 3-2 in the second set, and the Hungarian won the next two games as well.

Djokovic called for the doctor and asked for a bin to be put next to him because he was feeling so nauseous.

The 31-year-old was in real trouble when he went a break down early in the third set but he dug in to limit his losses and was urged on by his support camp, including wife Jelena.

A fillip came just in time as Fucsovics suddenly began to wilt, also calling for the doctor, and Djokovic won four games in a row to clinch the third set before both players gratefully retreated to the cool of the locker room.

Djokovic looked a different man on the resumption and did not drop another game as he booked a second-round date with American Tennys Sandgren.

Meanwhile, Roger Federer had the relative luxury of playing in the night session – although it was still hot – and breezed past Yoshihito Nishioka 6-2 6-2 6-4.

The second seed might have won even more comfortably but seemed in a hurry to get over the line and was broken for the only time serving for the match in a flurry of wild shots.

He put things right at the second time of asking though and goes on to face Benoit Paire in the second round.

Federer said: “I’m very happy to be back in New York healthy. I’m happy I never stumbled at the first hurdle. Almost time to retire but not yet. I’m happy I played well tonight.”

David Ferrer unlucky to play in era of game's all-time greats but deserves utmost respect

Roger Federer summed up the career of David Ferrer extremely accurately in just five words.

“Ultimate respect for road warrior,” the Swiss tweeted, reacting to Ferrer’s final Grand Slam match of his career at the US Open. It was a spot-on assessment, in which the tennis and sporting community would wholeheartedly agree.

Injury meant that the 36-year-old had to withdraw deep into the second set of his first round match against good friend and fellow Spaniard Rafael Nadal on Monday night.

It was a sad way for Ferrer, who will officially retire with either a swansong event in Madrid or Barcelona in his homeland next year, to end a significant but undeservedly understated career.

For a man known as tennis’ marathon man due to his heavy season workloads and ability to play out five-set epic encounters regularly, it didn’t seem right for a calf injury to break his once unbreakable body and bring his career to a premature halt.

It was the first time in 207 major matches he had had to pull out during a match, bringing a tear to the eyes of many watching under the lights on Arthur Ashe Stadium.

“This is my last Grand Slam. I’m so sorry because I can’t finish the match. I will miss you a lot,” Ferrer, a man of very few words, said.

The cliche would be to say the former World No3 (July 2013) made the best of his limited talent, small physical frame for a tennis player (5ft 9in) and lack of big weapons, aside from his consistency, work-rate and fitness, but that would be doing him a disservice.

He was better than that.

Turning professional in 2000, his peak years – between 2007 and 2015 – saw him finish in the top 10 for seven seasons out of nine, reach five Grand Slam semi-finals and one French Open showpiece, in 2013, in which he lost to compatriot Nadal.

It was remarkable level of play that, in any other era, would have seen him nick a slam. However, Nadal, Federer, Novak Djokovic, Andy Murray and Stan Wawrinka all stood in his way.

While his head-to-heads were all substantial losses with the aforementioned, aside from a 7-7 square-up with Wawrinka, Ferrer was always in the bracket of quality a few notches below those greats but better than most of the rest.

In other bygone eras, certainly between Pete Sampras’ decline and retirement in the early 2000s and before Federer’s emergence, Ferrer may have won a major or two, like the likes of Thomas Johansson, Marat Safin Lleyton Hewitt and Juan Carlos Ferrero did. Unluckily for him, his timing was a little out.

That, nevertheless, should not detract from a player who you would have playing for you if your entire life’s possessions were resting on the line. He never showed anything less than 110 per cent endeavour on the court.

Let’s also not forget, Ferrer did win 726 matches on the ATP World Tour – the most-ever by a player who did not go on and win a Grand Slam title.

Ferrer also helped Spain win three Davis Cup titles, prompting Nadal to describe him as “one of the greatest” in the country’s history.

Whether it was grinding from the back of the court on his beloved clay or grinding opponents down by retrieving near-impossible shots with his frenetic on-court speed and agility, Ferrer’s all-commitment style of play in a game which has become increasingly about power and strong hitting from the baseline, will probably not be seen too often again.

Ferrer’s never-say-die spirit was in fact the opposite to his quiet and shy persona off-court. Now with a young family, tennis is in Ferrer’s blood so expect him to move into the coaching sphere at some point next year when he fully hangs up his racquet.

Having also earned over $31million during an 18-year career (not including endorsements) – the seventh-most prize money in history – he has set himself up for the next phase in life and good luck to him.